Headboard for a bed



FIG. 1 is a perspective view of a headboard for a bed showing my new design, the broken lines are for environmental purposes only and form no part of the claimed design;

FIG. 2 is a front plan view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a first side view thereof; and,

FIG. 5 is a second side view thereof. 

The ornamental design for a headboard for a bed, as shown and described. 